Arteriovenous fistula of the lateral superior and inferior geniculate arteries. A unique cause of a "recurrent prepatellar bursa.

We report a previously undocumented case of an arteriovenous fistula of the superior and inferior lateral geniculate arteries presenting with what was thought to be a recurrent prepatellar bursa requiring repeated drainage and excision. The diagnosis was made by arteriography. Surgical exploration and ligation of the feeding and draining vessels, via a posterior approach, alleviated the symptoms. Vascular injury should be suspected in patients presenting with recurrent postoperative hematomas or hemarthroses following surgery on the knee.